TRACE ELEMENT CHARACTERISTICS OF MAGMATIC ROCK SERIES IN LANPING BASIN AND ITS NEIGHBORING AREAS
TENG Yan guo, LIU Jia duo, ZHANG Cheng jiang, NI Shi jun, PENG Xiu hong (Chengdu University of Technology, China)
Using NAA method, the authors studied REE and trace elements geochemistry of the magmatic rock series from Yongping Zhuopan, Yunlong Zaojiaochang, Erlongshan, Diannan, Madeng, Beiya, and Laojunshan in Lanping basin and its neighboring regions. At the same time, the authors discussed REE geochemistry characteristics, diagenesis style, tectonic environment of the magmatic rock series. The results show: (1) REE patterns of magmatic rock series are similar, and they are rich in LREE; (2) they have high La/Yb ratio, so the separation between HREE and LREE is significant; (3) Eu and Ce amormaly is not obvious. The magmatic rock series has high Rb, Ba, Sr, Th, U and low Ta. Combining the studies of REE, Trace elements geochemistry with that of isotope geochemistry, the authors think that the diagenetic source mainly comes from enriched mantle and partly from the crust, the diagenetic process is batch partial melting, and the diagenetic environment is continental rifting.